Some applications in which light-emitting diodes (LEDs) are used require components which react insensitively to electrostatic discharges (ESDs). Newer high-efficiency chip technologies with light-emitting diodes, however, often have a relatively large sensitivity to ESDs, for example InGaN or GaN diodes, in which case the electrostatic discharges can lead to breakdown of the pn junction with irreversible damage. This means that the maximum voltage peak which may occur in the event of an ESD is becoming more important for newer chip technologies.
To be able to process such components, it is necessary to ensure processing in an ESD-free environment, which can entail high costs to equip the production lines. For reasons of costs for processors of electronic components, retrofitting of processing lines to produce an ESD-free environment can only be envisioned in exceptional cases.
In another conventional approach for the protection of an optoelectronic component with respect to electrostatic discharges, a back-to-back diode or an Li diode may, for example, be provided, which is formed with an orientation antiparallel to the forward-bias direction of the optoelectronic component. In this way, an ESD event can always be dissipated via the diode connected in the forward direction as a function of its polarity, i.e. either the ESD protection diode or the optoelectronic component. Abrupt discharges at a diode connected in the reverse-bias direction can be avoided in this way.
In another conventional approach for the protection of an optoelectronic component with respect to electrostatic discharges, a series resistor, for example, with a resistance of 330 ohms (Human Body Model HBM), may be connected in front of the optoelectronic component to be protected. With the aforementioned conventional approaches, the ESD-sensitive component to be protected can achieve an ESD stability which corresponds to that of components with conventional chip technology. Nevertheless, the maximum voltage peak of the ESD pulse may be limited in these conventional approaches since very high electric fields can nevertheless cause damage at the active layers of the ESD protection diode, as well as at the optoelectronic component.
Furthermore, these ESD protection components require an area, for example, of at least 200×200 μm2, which is lost in the miniaturization of the actual optoelectronic component to be protected. At the same time, the ESD protection component may absorb light which is emitted, for example, by an optoelectronic component to be protected and, therefore, reduce the efficiency of the optoelectronic component to be protected.
DE 10 2012 208 730.3, the subject matter of which is incorporated herein, describes an optoelectronic component device and a method of producing an optoelectronic component device.
We provide an optoelectronic component device and a method of producing an optoelectronic component device, wherein the component device saves on costs and the area for an additional ESD protection diode.
An organic material is a carbon compound existing in chemically uniform form and distinguished by characteristic physical and chemical properties, irrespective of the respective aggregate state. Furthermore, an inorganic material is a compound without carbon or a simple carbon compound, existing in chemically uniform form and distinguished by characteristic physical and chemical properties, irrespective of the respective aggregate state. An organic-inorganic material (hybrid substance) is a compound comprising compound parts which contain carbon and compound parts which are free of carbon, existing in chemically uniform form and distinguished by characteristic physical and chemical properties, irrespective of the respective aggregate state. The term “material” comprises all materials mentioned above, for example, an organic material, an inorganic material and/or a hybrid material. Furthermore, a material mixture may for instance consist of constituents of two or more different materials, the constituents of which are, for example, very finely distributed. A material class is a material or a material mixture consisting of one or more organic material(s), one or more inorganic material(s) or one or more hybrid material(s). The term “substance” may be used synonymously with the term “material”.
Our optoelectronic component device may comprise: a first electrode and a second electrode, a first optoelectronic component electrically coupled to the first electrode and the second electrode; and a first electrically conductive section electrically coupled to the first electrode, and a second electrically conductive section electrically coupled to the second electrode; wherein the first electrically conductive section and the second electrically conductive section is arranged electrically in parallel with the first optoelectronic component; and wherein the first electrically conductive section and the second electrically conductive section are arranged, and configured relative to one another, such that, beyond a response voltage applied over the first conductive section and the second conductive section, a spark discharge occurs between the first conductive section and the second conductive section; wherein the response voltage has as its value a value which is formed greater than the threshold voltage value of the first optoelectronic component and less than or equal to the value of the breakdown voltage of the first optoelectronic component.
The actual response voltage of the spark gap for a component device may be dependent on the specific configuration of the electrically conductive sections and the dielectric between the electrically conductive sections so that a voltage range within which a spark discharge occurs between the electrically conductive sections at a particular spacing is often specified. For a spark gap, the typical breakdown strength of air as a dielectric may have a response voltage in a range of from approximately 1 kV/mm to approximately 3 kV/mm. In electrically conductive sections having a spacing of 1 mm, a spark can cross over, and a discharge can therefore take place when the potential difference between the electrically conductive sections has a value greater than approximately 3 kV. At the latest beyond this potential difference, the electrical resistance may be very small compared to the resistance of the optoelectronic component in the reverse-bias direction, for example, from approximately 0Ω to approximately 500Ω. Below approximately 1 kV, on the other hand, with a spacing of 1 mm and plane-parallel electrically conductive sections, a discharge is not to be expected.
For other dielectrics, the response voltage may be formed other than in air. With a constant spacing, the response voltage of the discharge path can be modified by the choice of the dielectric.
The electrically conductive terminals should be configured such that the value of the response voltage of the discharge path is formed between the threshold voltage of the electronic component to be protected and the breakdown voltage of the electronic component.
Up to the minimum value of the response voltage of the spark gap, the optoelectronic component should be able to operate regularly without a spark, i.e., a spark discharge, being formed between the electrically conductive terminals. A typical value of a threshold voltage of an optoelectronic component, for example, a GaN diode, may be formed from approximately 0 V to approximately 5 V. Below the response voltage, the spark gap may have a resistance which is as high as possible, for example, from approximately 1 MΩ to approximately 1 GΩ, and a small flow of current, for example, from approximately 10 μA to approximately 100 μA. The response voltage of the spark gap, i.e., the voltage which is necessary to form a spark discharge between the first electrically conductive section and the second electrically conductive section, therefore has at least a voltage value greater than the value of the threshold voltage of the optoelectronic component.
The voltage value of the discharge path, beyond which a spark discharge is formed, at the latest, i.e. the maximum response voltage of the discharge path at which the breakdown of the potential difference takes place should be formed below the breakdown voltage of the optoelectronic component since otherwise protection of the optoelectronic component against electrostatic discharges cannot be ensured. A typical breakdown voltage for such a component may, for example, be formed from approximately 170 V to approximately 200 V.
One configuration of the electrically conductive sections, which satisfy these conditions may, for example, have a spacing with a value of approximately 50 μm and an air dielectric. This configuration has the advantage that it can be produced, or configured, simply in terms of process technology.
In another configuration, the first electrode may comprise a different substrate and/or a different material than the second electrode, in which case a common substrate may also be understood as a common carrier.
In another configuration, the first electrode may be formed in a plane with the second electrode.
In another configuration, the first electrode may be formed in a different plane than the second electrode.
In another configuration, the first electrode or the second electrode may be grounded.
In another configuration, the optoelectronic component may be configured as an electromagnetic radiation-emitting component, for example, a light-emitting diode, a laser diode or a solar cell.
In another configuration, the optoelectronic component may be formed within an area of approximately 25 mm2, for example, in an area of approximately 1 mm2, for example, in an area of approximately 0.25 mm2, for example, in an area of approximately 0.09 mm2, for example, in an area of approximately 0.04 mm2, for example, in an area of approximately 0.01 mm2, for example, in an area of approximately 25×10−3 mm2, for example, in an area of approximately 25×10−6 mm2. The electronic component may in this case have a geometrical shape, for example, from the group of geometrical shapes: rectangular, square, hexagonal, polygonal or round.
In another configuration, the optoelectronic component may be formed on or over a lead frame, in which case the first electrically conductive section and/or the second electrically conductive section may be formed as part of the lead frame.
A lead frame may, for example, be understood as a metal structure which comprise one or more metal pieces and, for example, holds the metal pieces together by a metal frame. A lead frame may, for example, be formed by a flat metal plate, for example, by a chemical method, for example, etching, or by a mechanical method, for example, stamping. A lead frame may, for example, comprise a metal frame having a multiplicity of metal pieces subsequently forming electrodes which may be connected to one another and to the metal frame by metal webs. However, a lead frame may also be understood as the metal pieces formed by a metal frame as described above, which form electrodes, the metal pieces no longer being physically connected to one another by the metal, i.e., for example, after the metal webs have already been removed. The electrodes may therefore clearly form the lead frame itself or constitute separated parts of a lead frame.
A lead frame may in this case be understood as a conduction plane and/or metallization plane, in which case the conduction plane and/or metallization plane may even only be virtually, i.e. logistically, continuous, for example, as separated electrodes which geometrically lie on a plane and are formed to supply a component with electricity.
In another configuration, the optoelectronic component may be enclosed by a housing, in which case the housing may be formed as a package.
In another configuration, the first electrically conductive section and/or the second electrically conductive section may be formed inside the package.
In another configuration, the first electrically conductive section and/or the second electrically conductive section may be formed outside the package.
In another configuration, the first electrically conductive section may be formed as a region of the first electrode, and/or the second electrically conductive section may be formed as a region of the second electrode.
In another configuration, the optoelectronic component may comprise contacting, i.e. an electrical supply, from the group of contact arrangements: top contact, for example, a sapphire chip; bottom contact, for example, a flip chip; vertical contact, for example, a diode, the top contact and the bottom contact having a two-dimensional electrical supply configuration.
In another configuration, the device may furthermore comprise at least one further optoelectronic component, the further optoelectronic component being electrically connected in parallel with the first optoelectronic component, with the first electrically conductive section and the second electrically conductive section, for example, as a “multi-die light engine”.
In another configuration, the first electrically conductive section may comprise a different material than the second electrically conductive section and/or the first electrode and/or the second electrode.
In another configuration, the first electrically conductive section may be formed oriented relative to the second electrically conductive section, for example complementarily, perpendicularly, parallel, concentrically or diverging. A diverging orientation of the electrically conductive sections may, for example, be configured as a horn curve and/or Jacob's ladder. In this way, the spark discharge can be quenched when the voltage falls below the response voltage.
In one configuration, the electrically conductive sections may have a mutually complementary arrangement, in which case the first electrically conductive section may be formed partially and/or fully perpendicularly and/or parallel to the second electrically conductive section.
In one configuration, the electrically conductive sections may have an overlapping arrangement, i.e. an arrangement offset with respect to one another and/or an arrangement displaced with respect to one another, in which case parts of the electrically conductive sections may be mutually parallel, for example, at a distance from one another. The electrically conductive sections may also be formed in different planes in the sense of the plane of the drawing, for example, in a similar way to a cross.
In one configuration, a parallel arrangement of the electrically conductive sections may, for example, be formed as a partially and/or fully concentric arrangement and/or coaxial arrangement of the electrically conductive sections.
The second electrically conductive section may in this case form the inner electrically conductive region of a concentric arrangement of electrically conductive sections, in which case the interior of the second electrically conductive section may, for example, be hollow or may, for example, comprise an electrically insulating material or, for example, the same material, a similar material or a different electrically conductive material than the first electrically conductive section.
In another configuration, the surface of the first electrically conductive section and/or the surface of the second electrically conductive section, between which the discharge path is formed, may have a surface geometry from the group of geometrical shapes: flat, round, rough, acute and/or mutually complementary.
The surfaces of the electrically conductive sections, for example, between which the discharge path are formed, may also locally and/or globally have combinations of individual geometrical shapes with one another.
The geometrical shapes may be configured regularly in such a way that they have a geometrical symmetry axis, in which case the symmetry axis may have mirror symmetry and/or additionally rotational symmetry.
The electrically conductive sections may, for example, have a planar shape or a tapering shape.
A surface of electrically conductive sections may, for example, be formed in a similar way to a rod or pin, or be formed in a similar way to a planar plane.
Electrically conductive sections with a tapering shape may, for example, be formed in a similar way to a point or in a similar way to a rounding. With the tapering shape, the minimum value of the response voltage can be reduced, since the tapering shapes can locally have a higher field strength than planar shapes.
The surface may however also be partially or fully arbitrarily shaped, for example, by roughness or a coarse manufacturing process, for example, when the difference between the breakdown voltage of the electronic component and the threshold voltage of the electronic component is very great, for example, more than 200 V.
In another configuration, the shortest distance between the first electrically conductive section and the second electrically conductive section, between which the discharge path is formed, may have a value of from approximately 1 μm to approximately 100 μm.
In another configuration, the first electrically conductive section and the second electrically conductive section may be surrounded by encapsulation, for example, enclosed in a cavity, may be part of a section plane of a carrier of the optoelectronic component, or may be surrounded by a casting material which comprises, for example, an electrically insulating, crosslinkable organic and/or inorganic compound, for example, an epoxy resin or a silicone.
The encapsulation may be formed as mechanical protection for the electrically conductive sections such that the distance between the surfaces of the electrically conductive sections and the shape of the surfaces of the electrically conductive sections are protected in respect of external actions of force, for example, a collision, impact, falling or bending, against changes, for example, an increase or decrease in the distance or a deformation of the surface of the electrically conductive sections.
In another configuration, the encapsulation may be configured such that the dielectric, for example, air, is protected against environmental influences, for example, a change in the air humidity and/or an incidence of ionizing radiation, for example, UV radiation, X-radiation. These environmental influences could modify the necessary voltage which should be applied via the electrically conductive sections, in such a way that the formation of a spark discharge are formed at a value of the applied voltage which takes place below the threshold voltage of the electronic component to be protected, or above the breakdown voltage of the electronic component to be protected, and can compromise the function of the component to be protected or the ESD protection.
In another configuration, the material between the first electrically conductive section and the second electrically conductive section may comprise a material, or be formed therefrom, from the group of materials of electrically insulating, crosslinkable organic and/or inorganic compound, for example, an epoxy resin, a silicone or a ceramic.
In another configuration, the material between the first electrically conductive section and the second electrically conductive section may comprise a vacuum, or a gas, or be formed therefrom, from the group of gases, for example, oxygen, carbon dioxide, nitrogen, ozone or a noble gas.
In another configuration, the optoelectronic component device may be configured such that the optoelectronic component is protected against electrostatic discharges in the reverse-bias direction.
A method of producing an optoelectronic component device is provided, the method may comprise: formation of a first electrically conductive section electrically coupled to a first electrode, and of a second electrically conductive section electrically coupled to a second electrode; and coupling of a first optoelectronic component to the first electrode and to the second electrode; wherein the first optoelectronic component connects electrically in parallel with the first electrically conductive section and the second electrically conductive section; and wherein the first electrically conductive section and the second electrically conductive section are arranged, and configured relative to one another such that, beyond a response voltage applied over the first conductive section and the second conductive section, a spark discharge occurs between the first conductive section and the second conductive section; wherein the response voltage has as its value a value which is formed greater than the threshold voltage value of the first optoelectronic component and less than or equal to the value of the breakdown voltage of the first optoelectronic component.
In one configuration of the method, the first electrode may comprise a different material and/or a different substrate than the second electrode.
In another configuration of the method, the first electrode may be formed in a plane with the second electrode.
In another configuration of the method, the first electrode may be formed in a different plane than the second electrode.
In another configuration of the method, the first electrode or the second electrode may be formed to be grounded.
In another configuration of the method, the optoelectronic component may be configured as an electromagnetic radiation-emitting component, for example, a light-emitting diode, a laser diode or a solar cell.
In another configuration of the method, the optoelectronic component may have an external dimension of up to approximately 1000×1000 μl m2, for example, approximately 300×300 μm2, for example, approximately 250×250 m2.
In another configuration of the method, the optoelectronic component may be formed on or over a lead frame, the first electrically conductive section and/or the second electrically conductive section being formed as part of the lead frame.
In another configuration of the method, the optoelectronic component may be formed to be enclosed by a package.
In another configuration of the method, the first electrically conductive section and/or the second electrically conductive section may be formed inside the package.
In another configuration of the method, the first electrically conductive section and/or the second electrically conductive section may be formed outside the package.
In another configuration of the method, the first electrically conductive section may be formed as a region of the first electrode, and/or the second electrically conductive section may be formed as a region of the second electrode.
In another configuration of the method, the optoelectronic component may comprise contacting from the group of contact arrangements: top contact, for example, a sapphire chip; bottom contact, for example, a flip chip; vertical contact, for example, a diode, the top contact and the bottom contact having a two-dimensional electrical supply configuration.
In another configuration of the method, the device may furthermore comprise the coupling of at least one further optoelectronic component, the further optoelectronic component being electrically connected, or coupled, in parallel with the first optoelectronic component, with the first electrically conductive section and the second electrically conductive section.
In another configuration of the method, the first electrically conductive section may comprise a different material and/or a different substrate than the second electrically conductive section.
In another configuration of the method, the first electrically conductive section may be formed oriented relative to the second electrically conductive section in a perpendicular, parallel, concentric or diverging manner.
In another configuration of the method, the surface of the first electrically conductive section and/or the surface of the second electrically conductive section, between which the spark discharge occurs may be configured such that the surface has a surface geometry from the group of geometrical shapes: flat, round, rough, acutely tapering and/or mutually complementary.
In another configuration of the method, the first electrically conductive section may be formed with respect to the second electrically conductive section such that the shortest distance between the first electrically conductive section and the second electrically conductive section, between which the discharge path is formed, has a value of from approximately 1 μm to approximately 100 μm.
In another configuration of the method, an encapsulation is formed around the first electrically conductive section and the second electrically conductive section.
In another configuration of the method, the material between the first electrically conductive section and the second electrically conductive section may comprise a material, or be formed therefrom from the group of materials of electrically insulating, crosslinkable organic and/or inorganic compound, for example an epoxy resin, a silicone, a ceramic or a gas, for example, air, or a vacuum.
In another configuration of the method, the optoelectronic component device may be configured such that the optoelectronic component is protected against electrostatic discharges in the reverse-bias direction.